Improving graph-based overlay routing in delay tolerant networks

We present CGR-EB, a modification of, and extension to, the Contact Graph Routing (CGR) protocol - a forwarding mechanism for interplanetary communication. CGR-EB enables graph-based overlay routing for a variety of networks, including those using vehicular assets as data mules. It improves CGR by storing end-to-end message paths and encoding these paths, and the sub-graphs that spawned them, with the message. Simulation results demonstrate that CGR-EB reduces processing by up to two orders of magnitude, better tolerates errors in the network graph, and enables the use of cost functions that optimize system-level network state over individual message delivery. Graph-based overlay routing improves data exchange in mobility-enabled delay-tolerant networks by reducing or eliminating link negotiation and node discovery message overhead. CGR-EB provides the mechanism through which terrestrial networks may implement this routing approach.